Bloop

Bloop refers to a very large, low-frequency underwater sound detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) in 1997. The sound's origin was initially unknown and it was significantly louder than any known biological or artificial sound sources in the ocean. The location of the sound was in the South Pacific Ocean, near the southern tip of South America.

Analysis by NOAA scientists suggested that the sound originated from a living organism, as its characteristics did not match typical geological or man-made sounds. The waveform was described as a long, slowly rising frequency, lasting for about a minute. This led to speculation that it could be a very large marine animal, far exceeding the size of any known whale species.

However, in 2005, NOAA concluded that the Bloop sound was most likely generated by icequakes. These are seismic events that occur in large ice formations, such as icebergs or ice shelves, when they fracture or break. The unique acoustic properties of the sound are attributed to the way sound travels through ice and water. While the biological origin theory captured public imagination, the scientific consensus now points to a geological explanation related to ice activity.